defMON is the C64-software that I’ve been using for the last 15 years or so. My computer compadre Mad Frantic made it, and I’ve helped him out with a few suggestions and ideas over the years.
The newest version includes some new sync features, like synchronizing two defMONs by connecting two C64s to the same disk drive (or just straight into the other). You can now also nudge the tempo, back or forth, to stay in sync with your local brass band. So yeah, good times they are a coming!
We are also closer than ever to actually making some video tutorials to defMON so perhaps the number of defMON-users will rise to a two digit number in the future..